z/OS UNIX System Services (z/OS UNIX) diagnostic information is normally maintained in a set of cyclical buffers in memory. However, it can also be recorded to a file with a component trace. When it is maintained in memory, a dump must be taken to capture the diagnostic information for debugging purposes.

• To start the z/OS UNIX CTRACE from the console, enter:

  TRACE CT,4M,COMP=SYSOMVS 
  R nn,OPTIONS=(ALL),JOBNAME=(NFS_server),END 

  If you use the JOBNAME keyword on the statement, note that z/OS UNIX uses that parameter for USERID, not for job name. Specify the userid, not the jobname, for this parameter.
• Reproduce the problem in a system with minimal activity.
• Collect dump using console dump (see z/OS dump)
• To turn z/OS UNIX CTRACE off, issue the following console command:

  TRACE CT,OFF,COMP=SYSOMVS